Conventional fuel fired heaters utilizes flame combustion for producing heat, a process that is associated with the generation of both particles (soot, ash) and chemical emissions (CO, NOx) that are all harmful to the environment.
By replacing the flame combustion system with a catalytic oxidation system it is possible to eliminate fuel related emissions and at the same time increase the efficiency of the process by lowering the temperature of the oxidation process (through increased air flow). A primary feature of catalytic oxidation is that the process is not limited to a low air-to-fuel ratio, which results in complete oxidation of all hydrocarbons and lower temperatures in the reaction zone to a level at which NOx production is hindered.
A major challenge with a catalytic heater operating on a multi component liquid fuel, such as diesel or gasoline, is to start the heater in a cold environment without producing soot that can poison the catalyst, reduce the operating life of the heater and increase service cost for the end users.
The problems associated with starting-up a liquid fuel catalytic combustor has resulted in an industrial focus on gaseous fuels, such as natural gas and propane, for practical applications of catalytic combustion, as seen in U.S. Pat. No. 6,223,537, where natural gas is used to fuel the combustor.